Magnesium diboride (MgB2) has recently been found to be superconducting at the critical temperature Tc of ˜40 K, much higher than the best low-temperature intermetallic superconductors (Tc˜23 K). See, Nagamatsu J, Nakagawa N, Muranaka T, et al., Superconductivity at 39 K in magnesium diboride, NATURE 410 (6824): 63–64 Mar. 1, 2001. While its critical temperature is lower than for the cuprate superconductors, MgB2 is a classical superconductor behaving according to the BCS theory, like the existing low-temperature intermetallic superconductors. Unlike cuprates, however, MgB2 shows excellent conduction across grain boundaries and it is a simple, stoichiometric compound, very easy and inexpensive to synthesize. In the few months since discovery of its superconductive properties, MgB2 has generated a tremendous amount of research and interest.
Several factors would, however, seem to preclude widespread use of MgB2 as a superconducting material. Because it is a brittle ceramic, MgB2 is difficult to use in bulk form as a single phase. For instance, any cracks in the diboride phase will interrupt the superconducting pathway. The ceramic could be embedded in a tough, robust metallic matrix. This approach has been used with brittle cuprate superconductors (typically mixed and sintered with silver) and for the brittle, low-temperature intermetallic superconductor Nb3Sn (encapsulated in copper and cold-drawn as a Nb precursor). Such an approach would be difficult to achieve with MgB2.
The consensus is that the prior art relating to diboride superconducting materials has associated with it a number of problems and deficiencies, most of which relate to the structural and/or mechanical limitations of the superconducting phase. Accordingly, there is a need for one or more process and/or fabrication techniques, as well as related compositions of matter, to better utilize and benefit from the superconductivity of such materials.